FABRICATION OF NANOWIRES

• US 20090028488A1
• Filed: 10/12/2006
• Published: 01/29/2009
• Est. Priority Date: 10/12/2005
• Status: Active Grant

• Current Assignee: Adelaide Research & Innovation Pty Ltd. (University of Adelaide)
• Original Assignee: Aselaide Research & Innovation Pty Limited
• Inventors: Monro, Tanya, Ebendorff-Heidepriem, Heike
• Granted Patent: US 7,848,607 B2
• Time in Patent Office: Days
• US Class Current: 385/12
• CPC Class Codes: B29C 48/11 comprising two or more partially or fully enclosed cavities, e.g. honeycomb-shaped
• CPC Class Codes: B29C 48/475 using pistons, accumulators or press rams
• CPC Class Codes: B29D 11/00663 Production of light guides
• CPC Class Codes: B29L 2031/60 Multitubular or multicompartmented articles, e.g. honeycomb
• CPC Class Codes: C03B 2201/30 doped with metals, e.g. Ga, Sn, Sb, Pb or Bi
• CPC Class Codes: C03B 2201/82 Fluoride glasses, e.g. ZBLAN glass
• CPC Class Codes: C03B 2201/86 Chalcogenide glasses, i.e. S, Se or Te glasses
• CPC Class Codes: C03B 2203/02 External structure or shape details
• CPC Class Codes: C03B 2203/10 Internal structure or shape details
• CPC Class Codes: C03B 2203/14 Non-solid, i.e. hollow products, e.g. hollow clad or with core-clad interface
• CPC Class Codes: C03B 2203/16 Hollow core
• CPC Class Codes: C03B 2203/223 Matching viscosities or softening points of glass layers
• CPC Class Codes: C03B 2203/32 Eccentric core or cladding
• CPC Class Codes: C03B 2203/34 Plural core other than bundles, e.g. double core
• CPC Class Codes: C03B 2203/42 Photonic crystal fibres, e.g. fibres using the photonic bandgap PBG effect, microstructured or holey optical fibres
• CPC Class Codes: C03B 37/01205 starting from tubes, rods, fibres or filaments C03B37/014 takes precedence
• CPC Class Codes: C03B 37/01228 Removal of preform material C03B37/01251 takes precedence
• CPC Class Codes: C03B 37/0124 Means for reducing the diameter of rods or tubes by drawing, e.g. for preform draw-down
• CPC Class Codes: C03B 37/01274 by extrusion or drawing
• CPC Class Codes: C03B 37/0256 Drawing hollow fibres C03B37/02781 takes precedence
• CPC Class Codes: C03B 37/02781 : Hollow fibres, e.g. holey fibres
• CPC Class Codes: G02B 6/02366 : Single ring of structures, e.g. "air clad"
• CPC Class Codes: G02B 6/02371 : Cross section of longitudinal structures is non-circular
• CPC Class Codes: G02B 6/107 : Subwavelength-diameter waveguides, e.g. nanowires
• CPC Class Codes: Y10T 428/298 : Physical dimension

Abstract

A method of forming a nanowire is disclosed. In one embodiment, a primary preform is formed comprising at least one central region and a support structure. The primary preform is then drawn to a cane, which is then inserted into an outer portion, to form a secondary preform. The secondary preform is then drawn until the at least one central portion is a nanowire. The method can produce nanowires of far greater length than existing methods, and can reduce the likelihood of damaging the nanowire when handling.

Claims

1. A method of forming a fibre incorporating a nanowire, the method comprising:

forming a primary preform comprising a central portion and a support structure for supporting the central portion;

drawing the primary preform to form a cane;

forming an outer portion having a cane receiving portion for receiving the cane;

inserting the cane into the cane receiving portion to form a secondary preform; and

drawing the secondary preform until the central portion is a nanowire.

2. A method as claimed in claim 1 wherein the primary preform is formed by extrusion.

3. A method as claimed in claim 1 wherein the outer portion is formed to provide a space leading to the cane receiving portion.

4. A method as claimed in claim 3 wherein the space is a wedge-shaped cut-away in the outer portion.

5. A method as claimed in claim 3 wherein the method further comprises etching away at least a part of the support structure that is exposed to the space to expose the nanowire.

6. A method as claimed in claim 1 wherein the primary preform is made from a soft glass.

7. A method as claimed in claim 6 where in the soft glass is lead silicate.

8. A method as claimed in claim 1 wherein the primary preform is made from a polymer.

36. A fibre incorporating a nanowire, formed by the method according to claim 1.

9. A fibre containing a nanowire, the fibre comprising:

an outer portion defining the outer surface of the fibre;

a nanowire within the outer portion; and

a support structure between the outer portion and the nanowire supporting the nanowire.

10. A fibre as claimed in claim 9 further comprising at least one cladding region surrounding the nanowire.

11. A fibre as claimed in claim 9 wherein the support structure comprises at least one strut extending radially from the central portion.

12. A fibre as claimed in claim 11 wherein the at least one strut terminates at a wall portion forming a perimeter of the support structure.

13. A fibre as claimed in claim 11 wherein the support structure comprises four struts extending radially from the central portion.

14. A fibre as claimed in claim 13 wherein the wall portion defines a square in cross-section.

15. A fibre as claimed in claim 12 wherein the outer portion comprises a cut-out for providing access to a part of the wall portion.

16. A fibre as claimed in claim 13 wherein the wall portion defines three sides of a square in cross-section.

17. A fibre as claimed in claim 15 wherein the cut-out is wedge-shaped.

37. A sensor comprising the fibre according to claim 10 for sensing at least one parameter of an environment existing within the at least one cladding region.

18. A method of forming a nanowire, the method comprising:

forming a preform structure comprising a central portion supported by a support structure, and an outer portion surrounding the central portion and the support structure; and

drawing the preform structure until the central portion is a nanowire.

19. A method as claimed in claim 18 wherein the step of forming the preform structure comprises inserting the central portion and the support structure into the outer portion.

23. A nanowire formed according to the method of claim 18.

20-22. -22. (canceled)

24-31. -31. (canceled)

32. A method of forming a nanowire, the method comprising drawing a cane having a central portion supported by a support structure until the central portion is a nanowire.

33. A method of increasing the nonlinearity of a nanowire, the method comprising surrounding the nanowire with a nonlinear fluid.

34. A method as claimed in claim 33 wherein the nanowire is surrounded by a support structure and an outer portion, defining at least one channel in fluid communication with the nanowire, the step of surrounding the nanowire with the nonlinear fluid comprising introducing the nonlinear fluid into the at least one channel.

35. A method as claimed in claim 33 wherein the nonlinear fluid is carbon disulphide.

38. A method of forming a fibre incorporating a plurality of nanowires, the method comprising:

forming a primary preform comprising at plurality of central portions and a support structure for supporting the plurality of central portions;

drawing the primary preform to form a cane;

forming an outer portion having a cane receiving portion for receiving the cane;

inserting the cane into the cane receiving portion to form a secondary preform; and

drawing the secondary preform until the plurality of central portions are nanowires.

40. A method as claimed in claim 38 wherein the outer portion is formed to provide a space leading to the cane receiving portion.

46. A fibre containing a plurality of nanowires, the fibre made by the method of claim 38.

39. (canceled)

41-45. -45. (canceled)

47. (canceled)

48. (canceled)

49. A nanowire greater than 10 mm in length.

50. (canceled)

51. (canceled)